Engines, including diesel engines, gasoline engines, natural gas engines, and other engines known in the art, may exhaust a complex mixture of air pollutants. The air pollutants may be composed of both gaseous and solid material, such as, for example, particulate matter. Particulate matter may include ash and unburned carbon particles called soot.
Due to increased environmental concerns, exhaust emission standards have become more stringent. The amount of particulates and gaseous pollutants emitted from an engine may be regulated depending on the type, size, and/or class of engine. In order to meet these emissions standards, engine manufacturers have pursued improvements in several different engine technologies, such as fuel injection, engine management, and air induction, to name a few. In addition, engine manufacturers have developed devices for treatment of engine exhaust after it leaves the engine.
Engine manufacturers have employed exhaust aftertreatment devices called particulate traps to remove the particulate matter from the exhaust flow of an engine. A particulate trap may include a filter designed to trap particulate matter. The use of the particulate trap for extended periods of time, however, may enable particulate matter to accumulate on the filter, thereby causing the functionality of the filter and/or engine performance to decline.
One method of restoring the performance of a particulate trap may include regeneration. Regeneration of a particulate trap filter system may be accomplished by increasing the temperature of the filter and the trapped particulate matter above the combustion temperature of the particulate matter, thereby burning away the collected particulate matter and regenerating the filter system. This increase in temperature may be effectuated by various means. For example, some systems employ a heating element (e.g., an electric heating element) to directly heat one or more portions of the particulate trap (e.g., the filter material or the external housing). Alternatively, some systems may regenerate a filter system by utilizing fuel provided to the system. For example, an exothermic reaction may be created by providing fuel to a diesel oxidated catalyst, or the like. Still other systems may heat the exhaust gases upstream from the particulate trap, with the use of a fuel-fired burner that creates a flame within the exhaust conduit leading to the particulate trap. In this manner, the temperature of the exhaust gas is elevated to the point to promote regeneration of the diesel particulate filter.
In addition, in many engine applications, fuel priming is desired before the engine is started for full combustion. A priming pump may be disposed within an engine system between the fuel source and fuel transfer pump. Typically, a priming pump is used to remove air from the fuel system. Additionally, a priming pump may also be useful during fuel filter replacement events. Priming pumps may often be manually operated and consist of a plunger disposed within a barrel and selectively pump fuel from one check valve to another. When in use, an operator may have to manually reciprocate the plunger hundreds of times to properly prime the engine/new fuel filter.
It would be useful to have a single system to selectively provide fuel to an engine for priming purposes and to aftertreatment systems that may require the use of fuel, such as a fuel-fired burner used to regenerate diesel particulate filter. The present disclosure is directed toward one or more of the aforementioned technologies.